An inverted pendulum type vehicle herein described refers to a vehicle which includes a body and two or more rotary bodies (such as wheels) coupled to the body, the body being coupled to the rotary bodies so that the body can be tilted in the back-and-forth direction of the vehicle, and which can be moved by rotation of the rotary bodies while maintaining a state where the center-of-mass of the body or the center-of-mass of a total mass obtained by combining masses of objects such as the body and a passenger supported on the body is positioned upward of the position of the rotation center of each of the rotary bodies, that is, maintaining the inverted state of the body. Such an inverted pendulum type vehicle is disclosed in Patent Documents 1 and 2, for example.
An apparatus disclosed in Patent Document 1 is an inverted pendulum type vehicle including two or more wheels and a body supported by these wheels. Further, the body includes a pair of getting-on decks which extend in a traveling direction orthogonal to a direction of an axle connecting the centers of the two or more wheels, and on which the left and right feet of a passenger are respectively placed. Furthermore, a control for traveling of the vehicle is performed based on the detection results of a tile angle each of the pair of getting-on decks in the pitch direction (around the axle) and a tilt angle thereof in the roll direction (about the anterior-posterior axis of the vehicle that is in parallel to the traveling direction).
An apparatus disclosed in Patent Document 2 is a mobile robot including a coaxial two-wheeled mobile mechanism which controls a forward thrust using an inverted pendulum control. Further, the mobile robot is structured so that the upper body of the robot can be autonomously swung and tilted in the roll direction (about the anterior-posterior axis of the mobile robot that is in parallel to the forward thrust direction), and controls a swing posture so that a location of an intersection of a line extending a composite vector of a centrifugal force and a gravitational force acting on the center-of-mass of the mobile robot and a ground surface (road surface) supporting wheels is kept in an area between the left and right wheels. The structure for moving the center-of-mass suppresses overturn of the mobile robot or occurrence of a slip of the wheels due to the centrifugal force generated during a steep turn and an inclination of a road surface.    [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2006-1384    [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2006-136962